Embodiments presented herein relate generally to a wind turbine, and more specifically relate to a system and a method for protection of a wind turbine against extreme load conditions.
A wind turbine typically includes a set of two or more turbine blades and a nacelle mounted on a pylon structure. The wind turbine is configured to tap the power of moving wind and convert it into kinetic energy of the rotating turbine blades. The wind turbine is also equipped with a torque transmission mechanism for transmitting a torque from the rotating turbine blades to a generator. The generator converts the transmitted torque into electrical energy. The generated electrical energy is typically fed to a power grid. Power electronic converters may be used to feed the power in a form compatible to the power grid. The generator and a control system may be installed in the nacelle of the wind turbine. Alternately, the control system may be installed remotely from the nacelle. A primary function of the control system is to control the operation of the wind turbine and to optimize the power generation therefrom.
Wind turbines are dependent on wind for their operation, and perform optimally at particular wind speeds. Wind speeds lower than a threshold value may result in very low power generation. Wind speeds higher than the threshold value may result in excessive stress and load on the turbine blades and as a result may damage the turbine blades. Turbine blade damage not only increases the cost of power production but also decreases the amount of power harnessed from the wind turbine. The damage caused to turbine blades may result in significant down time and may reduce the power generation potential of the wind turbine.
Generally, wind turbines may be put out of operation during extreme load conditions arising from high wind velocity. While this prevents turbine blade damage, such a strategy is unable to avoid the down-time arising from the wind turbine being shut-down.
There is a continued need for a system that not only protects the wind turbine during extreme loading conditions but also maintains some continuity of power generation.